1. Field
This following description relates to a positive electrode for a rechargeable lithium battery capable of providing a high voltage and a rechargeable lithium battery including the same.
2. Description of the Related Art
An energy storage device based on an electrochemical reaction includes two electrodes, an electrolyte that transfers ions, and a separation film. The electrochemical reaction of the energy storage device is mostly a surface reaction occurring on the surface of an electrode, and is a non-uniform reaction.
The reaction may be categorized as (1) a mass transfer reaction where chemical species dissociated from the electrolyte are transferred to the surface of an electrode; (2) a non-faradaic reaction, which is an adsorption/desorption reaction where the transferred chemical species form a kind of electric double layer on the surface of an electrode; or (3) a faradaic reaction.
Herein, the reaction species may have a non-faradaic reaction in which the chemical species from the electrolyte form an electrical double layer on the electrode surface and they are desorbed, or a faradaic reaction in which they are directly provided with electrons and oxidized (or reduced).
An example of an energy storage unit using the non-faradaic reaction is a super capacitor (or electric bilayer capacitor). An example of an energy storage unit using the faradaic reaction is a lithium rechargeable battery. In order to improve power of a rechargeable lithium battery, a method to add power-enforcing material (capacitor component) to a negative electrode or a positive electrode, or both a negative electrode and a positive electrode, has been suggested. However, this approach has not yet reached a sufficient level.